Time of day announcing system



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June 14, 1932. c. w. KECKLER ET AL TIME 0F DAY ANNOUNCING SYSTEM Filed Jan.

12, 1951 9 Sheets-Sheet 2 m w n W SUNK vom A TTURNEY June 14, 1932- c. w. KECKLER ET AL 1,863,137

TIME OF DAY ANNOUNCING SYSTEM Filed Jan. l2, 1951 9 Sheets-Sheet 3 @y @@fm' A T TORNE V June 14, 1932- c. w. KECKLER ET AL.

TIME OF DAY ANNOUNCING SYSTEM 9 Sheets-Sheet 4 Y Filed Jan. l2, 1951 June 14, 1932. c. w. KEcKLl-:R ET AL.

TIME OF DAY ANNOUNGING SYSTEM Filed Jan. l2, 1931 9 Sheets-Sheet QQW NNW

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By @Mme/ff- A T TOR/VE v June 14, 1932- c. w. KECKLER ET AL. I 1,863,137

TIME OF DAY ANNOUNCING SYSTEM Filed Jan. L2, 19311' 9 Sheets-Sheet 6 VOLUME IND/CA TOR Cl W. KFC/L ER /NVE/VTOR$ AIE HAGUE.

BV @6MM A TTOR/VE V June 14, 1932- c. w. KECKLER ET AL 1,863,137

TIME oF DAY ANNOUNCING SYSTEM Filed Jan. l2, 1951 9 Sheets-Sheet '7 K /NVENTORSI ,BV @awww A TTORNF V June 14, 1932.

c. KECKLER ET AL 1,863,137

TIME OF DAYY ANNOUNCING'SYSTEM Filed Jan. l2, 1931 9 SheeS-Shet 8 Il u o n n0 n U Pf /NVENToRs/ag A TTORNEV June 14, 1932. C W, KECKLER ET AL 1,863,137

TIME OF DAY ANNOUNCING SYSTEM Filed Jan. l2, 1931 9 Sheets-Sheet 9 ALTE/PNA TE DE$K,CLOC/(,0SC/LLA TOR, REPEATER, AND REPEA TER ALARM C/RCU/ TS Ii @n O l L-E:

A TTORNEV Patented June L14, 1932 .Uni ran .sir Aires PATENT o1-"Rican i CHARLES 'W. K'ECKLER, OF SUMMIT, AND ALFRED 1E. .'HAGUE, OF WEST ,ORNG-E, NEW JERSEY, ASSIGNORS TOBELL TELEPHONE LABORATORIES, INCORPORATED, OF -N'EW YORK, N. Y.,.A"GORPOR'ATION 0F 'NEW YORK .-TIME'OF .DAY ANNOUNCING SYSTEM Application filedJanuary 12, 1931.

This' 'invention relates to telephone exchange systems land more lparticularly to ysystems in vwhich a subscriber by calling a particular 7line c'lesignation either lby dialing asin machine switching systems, or "by the aidof an operatorasfin manual systems, may obtain aconnection with a central time .an- `n'ouncing'bureau 'from which at specifiedinterval's' announcements are made of Ythe correct time of day. Theobject'of'theinvention isto'enabletime oi.g day announcements to be broadcast Vefciently to as vmany vsubscribers in an exchangearea or a plurality ofexchange areas, as requests the vtime of day at Vany 'period thereof.

VI-leretofore'it-'hasbeen proposed to provide va time announcingmechanism 4for .an ollice 'in Which a plurality of subscribers Vlines terminate which may be lautomatically vvselected by any Vcalling v'subscriber of the office through'the dialing of a line desi'gnation'set aside for that purpose. U pon the seizure Vof the vannouncing Vmechanism from one or a plurality of subscribers lines,the Imechanism through phonographic means, for example,

as is ydisclosed in Patent No. 1,227,523, granted't'o J. G. Blessingon March Q2, 1917, or through `photographic soimd `producing means, for .example as shown in Patent No.

,and do not Apermit'the centralization ofthe vservice in `a single operators position for enabling one operator to announcethe time on all calls'incoming from an extended area. ln Yaccordance 'with (the present invention, one embodiment 'of which "has been disclosed Serial No. 508,211.

by yWay `ot example, a single time Vannouncing vbureauemploying but a single operator may l`be reached from offices 'of exchanges Within "a largearea. For-example, a'time announcing bureau located in New York city mi'ghtbe yemployed vrfor serving all ofthe exchange areas surrounding New York city Within a radius-of 300 miles, the Vdistant exchange areasbeing connected tothe time bureauo'ver 'long distance trunk lines set aside for that purpose. Thus, when any subscriber in such an area desires the correct 4time it .is only lnecessary for vhim to call-a designated num ber, Afor example, iMeridian 4000, whereupon 'if lhis `line terminates in a lmanual exchange the operator will connec'this'line with a trunk extending through a local center lto the'time Vannouncing bureau, or li'his line terminates in adial switching olfice,he will upon dialing ithe designated number become connected-by automatic selector 'switches YWith a trunk extending .to the time "bureau through 'a distributing center.

.By suitably vtanning out the ltrunk lineterminating Yin the time announcing bureau through `intermediate and local 4distribution centers it is possible to enable the operator at the bureau to simultaneously announce 4the time to any `number-ot subscribers in an extended area'whom mayat any momentbe connected `tto the bureau `for the purpose of `receivingsuch time announcement.

`In lgeneral the system in accordance with thepresent invention functions as follows: It Will be assumed, 4for example, that a sub* scri'ber Whose line terminates ina dial switchyin'g'olli'ee in Philadelphia desires the correct time and dials the designated number, Meridian 4000. `In response to dialing, selec- '.tor lswitches yin rvthe local oilice 'at the Philadelphia exchange will establish'a connection with a `trunk `terminating in a distribution center local to the Philadelphia area land lmultipl'ed with other trunks extending 'to Vother oliices `at the Philadelphia 'exchange and with other Ytrunks extending -to other exchanges in nearby communities Ato a trunk lextending to van outgoing distributing Apoint `'located,lor example, in NewYork city. This Vtrunk at the Philadelphia distributing center would be provided with a one-way vacuum tube repeater for amplifying voice currents incoming thereto from the distributing point in New York city. Also incoming to the distributing pointin New York city and inul tipled'to the trunk extending to Philadelphia, other trunks Would be provided extending to local distributing centers located, for example, atNewark,.NeW Jersey; Easton, Penn- Sylvania; etc.. From this outgoing distributing point the multipled trunk would extend as a single trunk to the central bureau in New York city, also equipped with a repeater. Thus, the Philadelphia subscriber by dialing the designated number becomes connected over the trunk networkdirectly with the central bureau. At the same time many other subscribers located in the areas surrounding the local distribution centers in Philadelphia, Newark, Eastometc. maybe in direct connection with the central time bureau in New York city. Also from `the outgoing distributing circuit in New York city other trunk networks may extend northward through local distributing centersfor serv- Y ing northern New York and eastwardl for Vpolitan areasuch as New York city.

serving New England. Indeed itis con-l ceivable that with a single central time bureau located at some central point along the easternseaboard, the ent-ire eastern time `zone might be served.

It is of courseobvious thatthe system ac cording to the present invention might be used to give service locally to a vlarge metrof In that case the oiiWices of the areawould begrouped according' to ltheir location in the area into this. signaled to announce the time .indicated sections, each section being served bya local distributing center, thej local centers v.being connected by trunks extending to an outgoing distributing point associated with the central bureau located at some central position in the area.

At the time bureau. whenever a call, or any number of simultaneous calls ,are incoming over the trunk line terminating therein, va calling lamp signal is given to 'they operator to advise herzof that fact and a circuit ises- Vtablished ywhich is effective, in combination .withl a clock circuit associatedy with the operatorsfdesk, during a71/2 second interval priorv toy the next time announcement period to cutthrough the circuits extending trom the callingV lines that may be at the time con?.

nected to the central bureau'preparatory to transmitting the announcement. The clock circuit is arrangedl to indicate the hours, minutes and quarter minutes and just prior to the next quarter vminute period following the receipt of an incoming call the operator Y bythe clock. She then announces the time,

for example, by saying, When you hear the V :tone signal it will be exactly 5 and 521 minutes after voiclockf. When this exact vtime is reached the clock circuit extinguishes the signal and transmits a tone signal to subscribers lines which are connected to the central bureau. In this manner the operator announces Vclockcircuit ofthe operators desk, the re- 'ceipt of partial time announcements by calling subscribers is ,obviated In the establishmentof connections trom a dial switching office employing panel Vtype apparatus it has been kfound desirable to establish connections with trunk circuits outgoing to the central time vannouncing bureau in the saine general manner as connections Vare established to manual offices, that is', by

setting up a vclass of call condition in the subscribers central oiice sender of such a character as willcause the senderY to position a district selector and an o'iilce selector, if required, to select an outgoing trunk and to then transmit codes of impulses to the trunk. By thus assigning the same class des igiiation to callsv for the time bureau as are assignedor-calls to manual oilices, the necessity for a special setting oi. the class switch of the senderis obviated. Since, however, the numerical portion of the time bureau designation, in the example assumed the designa tion 4000, isnot employed, it becomes necessary to absorb the code impulses correspond- Ying to this designation transmitted by the sender to the Y trunk circuit. Provision is therefore made, in accordance with Ythe present invention, in the trunk circuit tor absorbing these impulses and-'signaling the sender following the receipt ot the last impulse so that the sender which is then no longer required may be dismissed. In accordance with the present invention, this signal ymay be sent V to ,the sender upon the receipt either Aof a final heavyv positive impulseotcurrent if the sender employed is arranged to vterminate the code iinpulsing by the transmission of such a heavy positive iinpulse or'after such an interval Vfollowing the receipt of the ylast negative impulse of the code impulsesasv .would vindicate that the l .sender has completed the transmission ot' code impulses.

Other vfeatures 'disclosed and described herein have been made Lthevbasis ofi'other colpending applications tiled concurrently hereaggirare? with. These `applications are ,the applicaztion ofR-F. Massonneau, Serial No. 508,209, ,the `application oit W. B. Prince, Serial No.

508,208., andthe application of H. G. lV. Brown, Serial No. `508,207.

A Iclearer conception ofthe scope and .purpiose yoi 'the Vinvention 4will .rbe obtained from ra consideration :of kthe following description attached draw- Yot which the line may become associated with a centraloiiice register sender, such portions ofia register sender shown in the lower portion ot Fig. l as are necessary to an understanding ofthe invention, and the schematic representation of a district selector and otfice selector by means ofwhich the line may Vbe further extended;

Fig.V 2 shows an outgoing trunk extending to a local distributing center, Fig. 3;

Figs. 3 and 4 taken together, show apparatus at a local distribuitng center, Fig. 3 showing an extension of the trunk of Fig. 2

-extending'over a two wire trunk to the outgoingdistributingpoint of F ig. 5, and at the leftrportion-of the ligure the supervisory circuits of other trunks similar rto thetrunks o'l Fig. 2 which are also multipled to the trunks of Fig. 3 and Fig. 4 showing schematically alternate repeater, supervisory and alarm circuits which lmay be used in place of similar circuits shown in Fig. 3;

Fig. 5 shows the other end of the trunk extending to the local distributing center of Figs. 3 and 4 and apparatus of an outgoing distributing circuit;

Figs. v6to 9 inclusive taken togetherl show apparatus at a central time announcing bureau. Fig. shows one desk circuit at the central bureau; Fig. 7 shows the clock circuit and Fig. y8 shows an oscillator circuit, the circuits of Figs. 7 and 8 being individual. to the desk circuit of Fig. 6. Fig. 9 shows schematically an alternate desk and .associated circuits which may be used in place ot Vthe similar circuits of Figs. 6 to 8 inclusive;

l0 is a diagram showing schematically ythe arrangement of trunkin g facilities for connecting a plurality of oiiices through local distributing centers and an outgoing distributing point with a. cent-ral time announcinfr bureau;

Fig. 11 is a diagram .showing how Figs. l to y9 inclusive should be assembled to disclose the detailed circuits of the invention.

Genera/,Z description of the mention .By referring to Fig. 10a general compredistributing icentei'.

4vention may be obtained, As previously stated, :the time of day 4announcing system in accordance with the Apresent invention contemplates Ithe establi-shmentfof a central bureau at which is positioneda special oper- `ator who, when demand arises, periodically announces 4the exact time within the nearest quarter minute. Obviously, if required, such operator could be providedwith facilities for announcing the time within closer limits, as for example, to the nearest tenth yof a minute. It is :intended that the centra-l bureau shallbe accessible from a plurality of otiices :of `an `exchangefarea'overa special trunk network tanued'out from such bureau. To .facilitate the interconnection of subscribers whose lines terminate .in eXchauge-ofiices of-an area to be served by the central bureau Awith the central bureau the exchanges or oiiices ot I,the area rare divided into sections, all o'iiices of va particular section having access to a local From 'the vlocal rdistributingcenters of a plurality of sections.

`trunks extend as schematically disclosed in Fig. 10 to an outgoing distributing point located contiguous to the central bureau at which bureau the trunks incoming to the outgoing-distributing point are connected to the deskcircuit at the central bureau.

lVhile the invention has been disclosed as applied to a system vin which all sections-of lrthe area may beserved directly `from the outgoing distributing point, it will v'be obvious that intermediate distributingr centers may be interposed between the local distributing eenters and the outgoing distributing lpoint as disclosed in detail 'in the copending application o'l R. F. Massonneau, l'iei'einbefore referred to. Intermediate distributing centers would probably be employed in a commercial installation but have not been disclosed herein in order to simplify the disclosure as .much as possible.

The apparatus of the originating oil-ice shown in Fig. l is of the well known panel type. The line lfinder 101,selector switches 102 and 145 and the link circuit of Fig. l may be oi the same type and function in the ysame fmanner as the similar apparatus disclosed and described in Patent No. 1.690.206

rissued to A. Raynsford on November 6. 1928. The sender may be ot the same type as disclosed in Patent No. 1.505.171 issued to F. A. Stearn August 19. 1924. Only such portions of these switches. link circuit and sender have been disclosed herein as are considered necessary to an understanding of `the invention. reference being made herein tothe above identified patents for a full detailed disclosure.

The repeaters 375 and 675 shown diagraminaticallvby 'the rectangles in Figs. 3 and 6 may be of thesame type as disclosed in detail in Figs. 3 and l2 of the application of ld. F. Massonneau above referred to. The

. which either the repeater 375 or lthe repeater 400 may be inserted by the operation of either switch 350 or switch 450. Other oiiices similar to oitice X may also havel outgoing trunks terminating in the local Vdistributingcenter and multipled to trunk 300. The repeaters 375 and L100 are arranged to transmit voice f currents in one direction only, that is,'from the central bureau towards the calling line in oflices such as X. From the input side'of repeaters 375 and 400a trunk 500 extends to the outgoing distributing point Fig. 5.

This trunk is also multipled as indicated Vat the right of 5to similar trunks which extend. to other local distributing centers such as is shown in'Figs. 3 and 4, and the extension of these trunks extends to the central bureau desk circuit 600 through contacts ot key 650. 'An alternate desk circuit 900 may be connected tothe extended trunk circuit in place of desk circuit 600 by the operation Y,of key. 950 to the right andthe operation of i Vkey 650 tothe left. Whenever adesk circuitisremoved from service bythe maintenance man through the operation of the associated key 650 or 950 it becomes connected to test line 652 on line 952 extending to the maintenance mans test position. An operators transmitter 601 and receiver .602 may be connected to either desk circuit by plug and jack connections. I

With .this general outline in mind the invention will now be considered in more detail. Assume that a subscriber A whose line terminates inoirice X initiates a call to obtain the correct time. The subscriber A upon removing hs receiver from the switchhook causesthe setting ofthe brushes of the line finder 101 upon the terminals of the calling `line and thekextension of circuits vfrom the calling line and district selectorV 102 over wipcrsot the link circuit line iinder selector 150'andsender selector 160 lto an idle sender.

' Y It will be furtherY 'assumed that the sender shown in the lower portion of Fig. 1 is idle and becomes associated with the calling line, whereupon a pulsing circuit is established from battery through th-epulsing relay 108,

wiper 110,.wiper 107 the upper rightlcontact of cafnr104f, the lower brush of line'nder'lOl over the subscribers line loop'returning over the upper brushof line finder 101, the lower contact of cam 103, wiper 105,'iwlper 109 to ground through the balancing coil 106. As soon as'this pulsing circuit is established the calling subscriber receives theusual dial tone and proceeds to dial the digits ofthe central time bureau designation which, it will be assumed, is MER-1000 ,thereby setting the registers of the sender to record the oce and line designations of the central time bureau number. l

As soon as the idle sender becomes associated with the district selector, the sequence switch associated with the district selector 102 advances to position 3 establishing the usual fundamental circuit from the control relay (not shown) at the district selector 102 through the winding of the sender stepping relay 116. Under the control Vof the oliice code registers of the sender,the district selector 102 is controlled in thewell known manner to select a trunk group extending to ofiice selectors. Following the selection of the proper trunk group, the district selector 102 functions to selectA an idle oiiice selector in the group such as the one indica-ted lat 145. As soon. as the district selector terminates its trunk hunting operation the sequence switch Vassociated therewtli advances in the well known manner to position 10 whereby a fundamental circuit is established over the conductors of the selected trunk for controlling the otlice selector 145.

This Jfundamental circuit may be traced from battery through the Vwinding of the control relay (not shown) of the otce selector 145, upper brush of switch 102,v lower contact et cam 111, wiper y112, wiper 1111, contacts of cam 113 of the sender control sequence switch 114, upper contact of cam 115, .winding of sender stepping relay 116, back contact of the vO counting relay 117, upper left and lower contacts of cam 118 associated with .y the oice senderv sequence switch (not shown), contact ot cani 119, wiper 142, wiper 120,

upper contact of cam 121, lower brush of se lector switch 102, to ground at thevoiiice selector. i v Y v Stepping relay 116 oi the sender and the control relay off the oiice selector 145 operate in this circuit, the otiice .selector rbeing Vmanner as would be the case if a call were to be made to a manual oiiice having call indicator equipment and consequently,a circuit becoines'closed for relay l25assoc1ated with 'he call indicator impulser 100 at the sender.

Th`s circuit may be traced from battery through the winding of relay 125, outer back contactV of -relay 123, to ground at the upper inf Contact of' cam 126 of the control sequence sWit'ch1'14 Relayy 125 upon energizing locksV over its innerflower front' contacts, the contacts of cam 128 to ground'v at the lower1 contact otcam- 1269 remaining'lockedI until the impulser switchl 100y leaves position 8;

Following theseizure ofltrunk 204, a control circuit is established from theV sender to thecontrol relay 205 of trunk -204 whichE mayAv be traced from battery' throughV the upper windingfo relay 205, upper back contact of relay 207, tip cond-uctor202fo trunk 204, tip

brushes of sWitches14-5;4 and 102i, lower' contactofcam 111, Wipers'112 and 141-', contacts of'canr 113, upper'cont-act of cam 115, winding" of senderL stepping relayx 1'16, winding of relayv 130; right contactsot caml 118, contacts of cam 1119, wipers 142- and 120,l upper contact ofcain 121-, ring brushes of switches 102 andV 145, ringi conductor 203v of trunk 204, inner upper back contact of relay 207" to groundthrough the lcwer'wi'nding ofrela-y 205. Relays 130 and' 205 energize vin this circuit. Upon the energization of'rclay 13G-the sender` sequenceAA switch isadvanced out' of position l 12, in which4 it is` standing; following the completion oii'oih'ceA groupselection, into position 14 in the manner fully set forth: in the patent to` F. A.' Stearn hereinbefore referred to; In position 14,. an obvious circuit is established for relay 12231 over the contacts oi' cam 124 whereupon the initial energizing circuity of relay 125 is opened. Since the sender is disclosed in' Fig. 1 as arranged to vtransmit a: final heavy positive impulse followingthe completion of the sending of code impulsesin accordancewith the line desigf nation registered, Fig. 2B Will be connected vto Fig: 2 by connecting the conductors extendingdownwardly from Fig; 2to the vline BwB with theA conductorsl extending upwardly froml Fig. 2B to the line 13j-B", the conduc-v tors extending below'the line BB in Fig; 2 being omitted'v andFig; notbeing'connect-ed.

Relay 205 upon operating connects ground from cam 143 in the office selector 145' over the sleeve brush of' selector 145, sleeve conductor 208 oltrunk 204, upper Vback contact of relay20`9', front contact of relay205, to the middle spring ofinterrupter 210; As soon as interrupter 21'0 makes its right contact the ground'on conductor 208 is extended through the winding of sleeve relay 211 which operatesy and locks directlyV to sleeve conductor 208, connects ground' at its inner lower front contact to the start conductor 221, and vestablishes. a circut for the peg count register over its lowermost front con-tact, the lower back contactV oflrelay 207, the inner lower normal contacts of relay 212to ground at the next to lower front contact ofv relay 21'1. After van interval' sufficient to permit the sender tov make. the usual trunk guard testi and to permit thek operation of the peg count register, interrupter 210 closes its left Contact establishing aV circuit for4 relay 207 from battery through' the upper lWindingofrelay207, the lower back contact of rela 20G, the upper iront contact of'relay 211i, le t contactfofinterrupter 2,10, to ground on conductor 208. Relay 207 upon operating locks overits upper winding, the lower back contactof re.- lay 206, the lower'front contact of relay'207, to ground at the next to inner lower; front contact of relay 211', opens the circuit of ther peg count register, disconnects the windings' of relay 205- from'. the tip and' ring conductors of trunk 204 and connects these conductors in a dry bridge including the Winding of polarized relay 213. This circuit may be traced from the tip conductor 202 of trunkv 204, upper front contact of relay 207, upper baclr contact ot'- relay 214, upper back contact of' relay 212, winding of polarized relay 21.3 in parallel with resistance 21'5, inner upper back contact of relay 212, innerl upper back contact of relay 214, inner upper front contact of relay 207, to ring conductor 2030i trunk 204.

Relay 205 releases without affecting, the circuits now established and relay 130 at the sender also releases thereby completing a circuit over its outer right baclrcontact through the neXt to outer front contact of' relay 128, contacts of4 cam 128 to battery through the winding of relay 1271 Relay 1'2"(v thereupon energizes closing a circuit from ground over its contacts, the lowermost front contact of relay 1:25, contacts oi cam 129 to battery through the magnet Windingof the impulser switch 100 for advancing the impulser switch out of postion 1, through position 8'. As soon as the switch 1100 leaves position 8, the locking circuit of relay 125 is opened' so that when the switch 1001 rotates around into position 1 it inds no operating circuit and is arrested after completing a single revolution. As it passes through a complete revolution, switch 1004 transmits a plurality of series of'code impulses to the trunk circuit of Fig. 2 in` the: Well known manner, a. series being transmitted' for each digit of the central bureau designation 4000.

VVit'h relay 123 energized and relay 130 deenergized, the circuit over which the code impulses are transmitted may be, traced in part from conductor 133, inner upper front contact of' relay 125, or the contacts of cam 135, middle left back contact of relay 130, next to inner front contact of relay123, lower'contact of cam 115', contacts ofIv cam 113 wipers 14'1 and 112, thence as previously traced' through the Winding of' polarized relay 213 of trunk circuit 204, returning over wipers 120 and 142, contacts of cam 119,` inner front contacts ofw relay 123, inner back contact ofr4 relay 130, upper front contactV of' relay 125, or upper contacts of camy 136 to conductor 134. The impulses of each series may consist in the usual manner of light positive and Ilight or heavy'fnegative impulses. Sinceall of theV positive impulses are light,

thepolarized relay 213 Vwhich is included inl the impulsing circuit does not respond. e

the sender, upon the completion of the transmission of the code impulses and the return of switch 100 to position 1, a circuit is closed for control sequence switch 114 for advancing it out of position 9, the circuit extending over the contacts of cam 137, contacts of cam 139, lowerinost back Contact ofv relay 125, to ground at the front contact of relay 127. As switch 114 advances from position 9 through position 91/2, a circuit is closed for transmitting a heavy positive impulsel over the impulsing circuit previouslytraced through the winding of polarized relay 213.d

At .the sender this current llows from battery over contacts of cam 138, contacts of s cam 140,inner upper back Contact of relay Y 125, thence over the circuit traced through not operate however in this locking circuity 126. i Relay the winding ofrelay 213, returning over the upper right and lower lett contacts of cam 136 to'groundover the lower contact of cam 213know operates and closes an obvious circuitrfor relay 209, relay 209 locking in series with relay 214 over al circuit exte ding from batteiyv through thewindings ot relays 209 and 214, inner front contact of relay 209, inner lower normal contacts of 'relay 212 to Aground at the nextk tov lower front contact of relay 211., Relayv 214 .does

being shunted by ground at the front contact ofrelay 213. As soon as thevheavy positivev impulse ceases when controlV sequence switch'114 advances beyond position 9%, polarized relay- 213 releases whereupon relay ,214 operates. The sender is advanced to the :talking yselection positionfollowing Ythe i transmission of 'the heavy vpositive impulse .Y inl turnV advancing the district selectorV sedition.

' relayy 207, inner quence switch to the Ytalking position and it? self becoming disconnected from the estab-l lished connection and restored to normal con- Relayv 214 upon operating disconnects the winding'ot relay 213 from the conductors of trunk 204 and establishes a circuit extending -from battery through the lower winding of t windings .of polarized relay 122. is not in such aldirectionV as will operate relay 122. Relay 205v upon operating establishes a cir- 'cuit for` relay 220, extending from battery throughl the winding'of relay l220, upper front contact of relay 209, front contact of.

relay 205, conductor 201' to ground at a front contact orelay V211. Y f

Relay 220 upon operating locks over its inner lower front contacts,inner lower front contacts of relay 207, to ground on conductor 201 and connects ringing tone from the source of ringing current 224 over the inner upper front contact of relay220, inner upper back contact of relay 206,v trunk conductor 203,

i'ing brushes of switches 145and 102, lower4 contact of cam 121, right windings of repeat-V ing coil 144, upper contacts of cam 111, brushes of switches 102 .and 145, trunk conductor 202, upper backcontact of relay 206, to ground at the uppermost front contact of relay 220. Ringing tone current is thereupon induced over the calling lineloop through the left windingsl of repeating coil 144 in an obvious manner, as a signalv to the calling subscriber that a connection hasbecome eX- tendedV from hisv line to the transmission network. Relay 220y fat lits contacts 223 alsov extends conductor 219 to the winding or' pickuprelay 212 and extendsconductor 222 over its lower front contacts through the lower fwindingof relay 207 and the upper winding of cut-through relay 206. The circuitsover conductors 219 andv222are closed inamanner hereinafter described.

In the preceding description it was assumed that the sender of Fig. 1 was equipped to transmit a iinal heavy positive impulse of current and that consequently Fig. 2B was connected to Fig. 2. It will now be assumed that the sender does not transmit a nal im pulse of heavy positive current. In that case Fig. 2B will not be connected to Fig. 2 but Fig. 2A will be connected by'joining the'conductors extending downwardly from Fig. 2'

to the line A-A ,with the conductors extendiig ipwardly from Fig. 2A to the line B-B will also bel employed. When the trunk 204 is seized relays 2.05,'211 and 207 operate in the manner' previously described and relay 207 upon operating disconnects the winding of relay 205v from the fundamental circuit extending to the sender and connects the winding of polarized relay 225 in vseries with the winding of relay 130 in the sender.

YRelay 225 does not ,operate in this circuit, but

relay 130 operates'and prepares the circuit of the senderv for transmitting code impulses in the manner previously described. When the impulser switch 100 returns to position 1 after completing the transmission of the code impulses and advances switch 114 from position 9 to position 10 yno, heavy positive impulse of current will be transmitted as in this case the cain cuttings for connecting battery and ground toY the, control circuit asY sequence switch 114 passes vthrough position 91/2 will be'omitted from cams 126 and 138.

The conductors looped below line Y When` switch 100 advances, transmitting the usual negative impulses of current, thev code impulses because before interrupter 229Y advances to close its left contact to complete the circuit of relay 220 over the lower contactsof relay 226, polarized relay 225 will respond to a negative code impulse and shunt yrelay 226-to cause its release. Thus during the transmission of the code impulses relay 225m. responding to each negative impulse will shunt relay 226 and since these negative impulses-a rive periodically at intervals less than the interval required for interrupter 229 to complete av cycle, relay 226 cannot establish the circuit of relay 220.

, Upon the completion of the transmission of the code impulses however, relay 225 will receive noinore negative impulses and will remain deenergized thereby permitting relay 22G-toreenergize and remain operated during a complete cycle of interrupter 229, whereupon the circuit of relay 220 will be closed from battery through the winding of: relay 220, lower front Contact of relay 226, left contactsoi`I interrupter-229, lower back contact ot relay 206, inner. lower front contact oi relay 207 to ground at a contact of relay 2111". Relay 220 will therefore operate and perform the functionsr previously described, that is, will connect ringing tone from the source 224 to thecalling line and will extend conductors 219 and 222 tofrelay 212 and to relays 207 and 206 respectively.

llt` will be recalled that when the trunk 204' was iirst seized, relay 211 operated and connected ground to startk conducto-11221. A start circuitf was` thus closed from ground on startcon/luctor 221, normal contacts 301 of switch 350, back contact of relay 302 to battery through the winding of relay 303 at the local distributing center. Relay 303operates andV connects the polarized relays 3041 to 307 inclusive to the conductors of trunk 500 in series with the windings oi relays 501 and 502at the outgoing distributing point; The circuit thus established may be traced: from battery through the lower windings of. relays 501 and 502, the lower back contact' of relay 503, the lower left winding of. repeating coil` 504, lower contacts of jack 521, con( uctor.l 505 ofv trunk 500, contacts 303 of: switch 350, lowerright winding of repeatingA coil 309, upper contact' of relay- 303, windings oi relays 304 to 307 inclusivel upper right winding of coil 309, contacts 310 of switch 350, conductor 506 of trunk 500,y

and 307 are so polarized that they operate in this circuit but relays 305 and 300l being oppositely polarized, do not operate. Relays 501 and 502 also operate to perform functions to be described hereinafter; Relays 304 and 307 upon operating establish obviousl circuits for relays 311, 312 and 313. It is to be noted in this-connection that thestart' con ductor 221 is multipled to all trunks such as 204 extending from the several-oilicesliawf'- ino access to the local distributing center disclosed in Figs. 3 and 4, so that when any subscriber in suchy oiiices initiates ay calli for time of day service, the start relay 303 will be operated.

lelay'311 upon operating closes obvious circuits for relays 314 and 315.` Relays 312 and 313 also close circuits for other relays similar to relays 314 and 315. Since itis possible to operato four relays similar to relays 314 and 315 over each groundedv Contact olf relays 311, 312 and. 313, it is possible tothus operate twenty relays, and since each relay such as 315is capable when operated'oi con-- necting ground to five conductors such as 219, the operation oi" polarized relays 304 and 307 may thus control the grounding oil one hundred conductors 219 of one hundred trunks 204. TWhen conductor 219 of. trunk 204 is grounded through the operation of relay 315, the circuit of pick-up relay 212 is completed and relay 212 operates andl locks from battery through its winding and inner lower alternate contacts to ground at the nent to lower front contact of relay 211. At its 'loweri'nost normal contacts, relay 212' opens seized for use by other subscribers in oliicesy connected to the local distributing center arc simultaneously operated'through the opera'- tion of relays 314, 315 etc.

Operation of Zine z'fn, trouble alarm Shouldthe trunk circuit 500 be'introuble so that when the start relay 303 connects the relays 304 to 307- inclusive thereto, relays 304 and 307 do not operatekand consequently relay 311 does not operate, a circuit is established for operatinfr slow to operate relay 316 extending from battery, winding of relay 316, lower contact of relay 303, back contact of relay 311, back contact of relay 3117 to ground. Relay 316 operates, causing slow to operate relay v318 and relays 319 and 320 Y u to operate in turn. Relay 319 connects hold-- 1c" ing ground to the winding of start relay 303 to hold itoperated until the trouble condition is removed, and relay 320 grounds con-l ductors extending to the alarm board shown diagrammati'cally bythe rectangle 321. This alarm device may comprise suitable lamps or signal devices for indicating to a maintenance man that a trouble condition exists on the trunk line.

in response to the alarm signals, the maintenance man depresses the key 322, thus releasing relay 320 whichv opens the circuit of ythe alarm signals and establishes over the -upy guard lamp is atthis time lighted, the reoperation of thealarm signals indicates to the maintenance man'V that the trouble has been cleared, whereupon he releases key 322 extinguishing the guard lamp and releasing relay 320. Y

Extension of start circuit lo central bureau It will now be assumed tl at the operator is on duty at the central bureau and has plugged her announcing transmitter 601 and headset 602 by plugs 603, 604 and 605 into jacks 606, 607 and 608 of the desk circuit 600 and that consequently relays 609 and 610 are operated, relay 609 being operated overthe make spring of jack 606 and relay 610 being operated Vin a circuit from battery through the upper winding of relay 610,

lsleeves of ack 606 and plug 603, transmitter' 601, tips oi plug 603 and j ack 606, right vwindings of repeating coil 611 to ground through the lower winding of relay 610. Relay 610 in turn closes an obvious circuit for relay VVA612 which in turn. closes an obvious circuit 55e for relay 613. Relay 612 upon operating establishes the lament circuit for the repeater y 675 extending from battery at the repeater,

conductor A667, lower contact of relay 612,

conductor v663, filaments of the vacuum tubes of repeater 675 to ground'for lighting the filaments in the manner set forth in the application of R. F. Massonneau above referred to.

Relay 613 upon operating closes an obvious circuit for relay r614, prepares at its lower- 'most contacts a circuit for repeater alarm device 676 and closes a break in the start conductor 507 at its upper contacts. If the vacuum tubesy of 'repeater 675 have energized properly and cause the flow of space current, the alarm circuit prepared by'relay 613 will not therefore be closed through the operation of relay 613. Relay 614 upon operating closes an obvious circuit for relay 615 anda circuit for relay 617 extending from battery, winding of relay 617, back Contact of relay 616 to ground at the upper contacts of relay 614. At its inner lowerl front contact, relay 615 connects battery to the filaments oi the volume-indicator 618 which may be of the type disclcsedinPatentNo. 1,523,827 granted J anuary 20, 1925 to E. L. Nelson, and at its lower contacts closes the lilament circuit of the vacuum tubes 801 and 802 of the oscillator circuit 800. This lament circuit may be traced `from the filament battery through resistance 803, the filaments of the tubes in series, resistances 804 and805, conductor 806, contacts of relay 615, conductor 807 to the other terminalV of the lilament battery.

When relays 501 and 502 at the outgoing distributing point, Fig. 5, operate as previously described, a start circuit is established from ground at the contacts of these relays over conductor 507 which is multipled to other start conductors controlled by similar relays 501 and 502 in trunks similar to trunk 500 extending fromother local distributing centers, such as is shown, in Figs. 3 and 4, upper front contact of relay 613, back contact of relay 619 to battery through the winding of relay 620. Relay 620 which is slow to operate in turn establishes an obvious circuit for slow operating relay 621 which in turn operates and connectsthe winding of relay 622 to the start conductor 507 Relay 622 which is slow to release, in turn Vcloses an obvious circuitfor relay 623. Relay 623 connects the start conductor 507 directly to the winding of relay 622, closes an obvious circuit for relay 619 and an obvious circuit for call Vlamp 624. Lamp 624 lights as a signal to the operator that a Vcall for time of day has beenv initiated by a calling subscriber. When relay 619 operates it opens the circuit of relay 620 which releases, in turn releasing relay 621. Relay 621 in turn opens the initial operating circuit of relay 622, but relay 622 is now held operated over the upper contacts or" relay 623 so that relays 623 and 622 remain operated so long as thereis a ground on start conductor 507, indicating that a demand .existsvsomewhere in the area for time of day service. The purpose of the slow to operate relays 620 and 621 is to prevent a false signalfroin being given by reason of a momentary operation'of relays 501 and 502 which might be caused due to line surges when disconnection takes place. The slow to release relay 622 is used to hold relay 623 operated over the pe- Vriod .when relays 501 and 502 momentarily release when battery and ground are reversed through their windings as will be hereinafter described.

When relay 619 operates, it establishes a circuit from ground over its upper contact, conductor 626, the normal contacts of relay 700 to battery through the winding of relay 701. Relay 701 upon operating prepares a holding circuit for itself and establishes a circuit for relay 702 extending from battery, winding of relay 702, back contact of relay 703, upper back contact of relay 7 04 to ground the lower contact of relay 701. The operation of relay 702 connects ground to conductors 705 and 706 which extend through back contacts of relay 627 to conductors 628 and 629 extending to the outgoing distributing point and conductor 628 extending thence through the windings of relays 508 to 511 inclusive in parallel to battery. Conductor 628 may also extend through the windings of a second group of four similar relays it the area is large enough to require more trunks outgoing from the central bureau than can be served by the four relays 508 to 511 inclusive. Conductor 629 in a similar manner may be extended through the windings of four or eight additional relays similar to relays 508 to 511 inclusive. It will be noted that relays such as 508 and 510 each serve tive outgoing trunks such as 500, and consequently as many as forty trunks may be served, although it is intended that not more than thirty-six working trunks shall be connected at one time to the desk circuit of Fig. 6, the remaining four trunks being held in reserve for emergency purposes.

Transmission of cut-through swperm'sory/ signal When ground is connected to conductor 628 and relay 508 operates, it establishes a circuit for relay 503 extending from battery. upper winding of relay 503, lower contacts of key 512, inner back contact of relay 513 to ground at the inner front contact ot relay 508. Relay 503 upon operating in turn extends operating ground from the front Contact of relay 508 over the frontcontact of relay 503 to battery through the winding of relay 517. Relay 517 upon operating establishes a holding circuit from ground at its lower contact through the lower winding of relay 503. `When relay 503 operates, it disconnects the upper windings of relays 501 and 502 and ground from trunk conductor 506 and the lower windings ot relays 501 and 502 and battery from trunk conductor 505, and when relay 517 operates, the upper winding of relays 501 and 502 and ground are reconnected to rtrunk conduct-or 505 and the lower windings of theserelays and battery are reconnected to trunk conductor 506, thus re` versing the direction of current flowing over the conductors of trunk 500. In a similar manner relays 508 to 511 inclusive and other relays connected to conductors 628 and 629 cause a current reversal on other trunks similar to trunk 500.

y The reversal of current flowing over trunk 500 now causes the release ot polarized relays 304 and 307 and the operation of polarized relays 305 and 306. Relays 30-'11 and 307 upon releasing in turn release relays 311, 312 and 313 which in turn release all relays 31e and 315 which have been operated. Relays 305 and 306 upon operating close obvious circuits ior relays 317 323 and 324. Relays 317 upon opera-ting closes obvious circuits for relays 325 and 326 and relays 323 and 324 also close close circuits for other relays similar to relays 325 and 326. Since it is possible to operate four relays similar to relays 325 and 326 over each grounded contact ot relays 317, 323 and 324, it is thus possible to operate twenty relays, and since each relay such as 326 is capable when operated of connecting ground to five conductors such as 222. the operation oi polarized relays 305 and 306 may thus control the grounding of one hundred conductors 222 of one hundred trunks 204.

When relay 326 operates to connect ground to conductor 222 with relays 212 and 220 operated as previously described, a connection is extended from ground on conductor 222 through the lower front contacts ot relay 220, lower winding of relay 207, upper winding of relay 206 and lower alternate contacts of relay 212 to battery. Cut-through relay 206 operates and locks over its lower winding and lower front contact to ground at a contact of relay 211, disconnects the source of tone current 224- froin the calling line and opens at its lower back contact the locking circuit of relay 207. Relay 207 however is held operated in series with relay 206. The operation of relay 206 also closes the talking conductors oli trunk 204 through condensers 230 and 231 and resistances 232 and 233 to trunk 300 of the transmission network, thus bridging the calling line A on in parallel with other subscribers who are receiving service at the same time. The calling subscriber can now hear the announcement but disturbances or cross-talk between his line and the network are very largely prevented by condensers 230 and 231 and resistances 232 and 233.

Operation of clock circuit Returning now to the operations which take place at the central bureau, it will be recalled that relay 702 operated to transmit supervisory impulses for causing all connected subscribers lines which have initiated calls for time of day service to be cut through to the transmission network. A further consideration of the clock circuit disclosed in Fig. 7will now be had. The central bureau is provided with a master clock disclosed in ating cam of the clock, the relay 713 at that the dot and dash rectangle 7 07 which is synchronized' by a district master clock every hour.y Impulses sent out by the district mas-v ter clock operate relay 708 which` connects battery to the synchronizing magnet 7 09, thus keeping the master clock 7 07 in synchronism with the district master clock. .The winding contacts 710 of the master clock arefarranged to close every sixty minutes and te remain Vthe correction of the clock from the district Vclock is made on the evenhour or fifteen minutes'past the hour, the contacts 717 close and thev contacts 716 are lifted off-the opertime operating over the hour contacts 717. Each time that relay 713 operates, vit closes a circuit over the right normal contact of key 718 through the winding of magnet 719 of the electric position clock 720.

When the time indicatedby the position clock 720 does not agree with the time indicated by the master clock 7 07 it may be reset by the operation of key 718 to its right or stop position or to its left or step position as required.` If the position clock is behind the master clock, by operating the key to the step position in which position it does not lock, the clock maget 719 will begiven an 'additional impulse over a circuit' extending through the magnet winding, rightnormal Contact of key 718v to ground over the left alternate contact of key 718 to advance the clock 71/2 seconds. As many koperations of key 718 to the left may be made as may be required to properly synchronize the clock 720 with ithe'master clock 707.' If'thev position clock is `ahead'of 'the master clock, the key 718 may be operated to its right or locking positiomthereby stopping the advance of the position clock until it indicates the correct time. Thislclock 720 should read 71/12 seconds faster than the master clock. f It is the form of a veedometer and is graduated in minutes, quarter-minutes, and hours. When the time is 71/2 seconds past the even minute, the fractional minute wheel of clock 720 should read one-quarter, vand when it is fifteen seconds past thev minute there should be no indication onfthe fractional minute wheel.

ters and even minute.

Each time that relay 713 operates from the The same applies for the one-halfthree-quarmaster clock circuit in additionto advancing the position clock, it also closes a circuit eX- tending from battery through resistance 721, winding of relay 7 22, lower normal contacts of'relay v704 to ground at the upper contacts of relay 713, and from battery through resistance 723, winding of relay 724, normal contacts of relay 7 04 to ground at the upper contacts of relay 713. Relay 722 operates ,but relay 724 does not, as it is at the time shunted .over its lower back contacts by ground on the upper contact of relay 713. Relay 722 upon' operating causes relay 704 to operate over a circuit extending through the winding of relay 704, front contact ofl relay '722 to ground at the back contact of relay 725. Relay 704 at its upper-back contact opens the circuit of relay702which as will be recalled, was instrumental in causing current reversals at the outgoing distributing `center for causing subscribers lines to be cut through tothe network. At its loweralternate contacts relay 7 04 establishes a holding circuit for relayj722 extending through the winding of relay 722, alternatel contacts of relay 7 04 to ground at the back Contact of relay 725.

After 0.5013' a second, relay: 713 releases and opens at its upper contact, the shunt circuit around the winding of relay 724, whereupon relay'7 24 operates over the locking circuit 'of relay 7 22 and closes an obvious' circuit forrelay 700, which in turn closes an obvious circuit for relay 703 and closes a locking circuit for relay`7 01 extending overt-he upper contacts of relay 701 the upper alternate contacts of relay 700 togronnd'on the start conductor 6.26. Relay 703 upon operating closes an obvious circuit for relay 726, opens another point in the circuitof relay 702 and closes a circuit-for announcing lamp 630,`ei:- tending over conductor 631, the upper front contacts of relay 7 03, the upper front contacts of relay 7 04 to ground at the lower contact of relay 701. The lighting of lamp 630is a signal to the operator that she should announce into her transmitter 601 the time indicated on the position clock 720. Shc'inay, for example, use the expression, l/'Vhen vyou hear the tonevsignal it will be exactly 53h/, minutes after five oclock.` The transmission circuit by means of which the announcement isV transmitted to Acalling subscribers connected to the network will be described hereinafter.. f, I

After .approximately 7 .1/2 seconds, the contacts 710 again close and "relay .7 13 operates, causing the clock 7 20 to advance 71/2 seconds and closing a shunt around the winding-of relay 7 22 extending from ground at the back lcontact of relay 7 25, alternatecontacts of relay 704,A winding of relay'722,y lower front K contacts of relay 724 to ground at the lupper contact of relay 713. Relayy 722 thereupon releases and closesV a circuit for relay 7 27 extending through the winding of relay 7 27 lower front contact of relay 726, back contacts l' of relay 7 22, upper contacts of relay 701, upper alternate contacts of relay 700 to ground on conductor 626. Relay 722 also connects ground from conductor 626 over the inner front contact of relay 726, conductor 728 to battery through the winding of relay 682, thereby operating relay 682, and also opens the circuit of relay 704 which thereupon releases. The release of relay 704 opens the circuit of the announcement lamp 680.

With relays 727 and 682 operated, a tone circuit is established fromthe oscillator 800 to the tallring conductors of the desk circuit 600 which may be traced from conductor 518, left normal contacts of key 650, upper front contacts of relays 617 and 682, conductor upper Contact of relay 7 27, left windings of repeating coil 7 29, lower contact of relay 727, conductor 684, lower alternate contacts of relay 682, lower contacts of relay 617, left normal contacts of key 650to trunk conductor 520. From trunk conductors 518 and 520, this circuit is exten ded to the calling'subscrib ers line as will be hereinafter described. Tone current is induced from the oscillator circuit 800 through thev right winding of repeating coil 729 over conductors 808 and 809. The operator is also enabled to hear this tone for checking purposes over a circuit extending from conductor 688, conductor 688, condenser 687, sleeves of jacks 607 and plug 604, headset receiver 602, sleeves of plug 605 and jack 608, condenser 686, conductor 685 and conductor 684.

Then relay 718 releases when contacts 716 of clock 707 again open after 0.5 of a second, relay 724 which has been held operated over the lower normal contact of relay 704 and the upper contact of relay 718 releases in turn releasing relays 700, 708, "26, 727 and 682. Relay 701 will remain operated if a call still exists for time of day service, and with relays 704 and 708 released, will again close the circuit of relay 702 which. will perform the function previously described of causing a cutt-hrough of any subscribers lines which may have initiated calls during the preceding 7% seconds. rllhe clock circuit thus functions to cause a cut-through signal to besent out upon the network followed by the lighting of the announcement lamp 680 and then followed by the application of a tone signal from the oscillator 800 every fifteen seconds as long as there are existing calls. The cutting through of the trunlrs which have waiting calls occurs approximately 0.5 of second f before the announcement lamp 680 at the relay 700 operates, ground is connected to conductor 626, but relay 701 cannot then operate as it is disconnected from conductor 626 at the uppermost contact of relay 700. After the announcement period, relay 700 releases as previously described, causing relay 702 to operate. At the beginning of the next 71/3 seconds before the succeeding quarter of a minute, the lamp 680 will light as previously described. This arrangement insures that the announcement lamp will always be lighted at the beginning of the announcement period in order to give sul'licicnt time to make a complete announcement. lNhen there is no call. waiting and therefore no groundv on conductor 626, relays 718, 722, 724, 704, 7 00, 708 and 726 operate in the manner previously described, but relays 701, 702, 727 and 682 do not operate.

ln order to have the clock circuit of Fig. 7 synchronized to indicate the start of the announcement period to the operator 71/2 seconds before the quarter minute periods, it is necessary to operate relay 722 with relay 724 short-circuited. This condition may be obtained without disturbing the position clock 720, by operating the key 718 to the right and then releasing it to normal during the first half of any quarter of a minute as read on the second hand of the master clock 707 or during the period the second hand is passing over a white segment of the second hand dial. Then key 718 is thus operated, relay 725 operates and removes the operating ground from relay 704. lll-hen the key is restored, relay 725 releases.

Operation of repeater at local distributing center lt will be assumed that the switch 850 at the local distributing center and key 650 at the desk circuit are all in their normal positions. lVith switch 850 normal, filament battery is connected to the filaments of the tubes or repeater 875 from battery at the repeater over conductor 849, normal contacts 827 of switch 850, conductor 848 through the tube filaments to ground in the manner disclosed in the application to R. l?. Massonneau hereinbefore referred to. lf the tubes are properly energized and emit space current a plate circuit relay not shown) in the repeater will operate. lf, however, the filaments do not light or the tubes do not emit space current, this relay will not operate, and a circuit is therefore closed from ground at the back contact of this relay over conductor 844` contacts 828 of switch 850, upper normal contacts of jack 829 to battery through the winding of slow to operate relay 880, and through resistance 888 and the inner normal contacts of jack 829 through the winding of slow to release relay 884. Relay operates first and removes a short circuit from relay extending from battery through the winding 

